#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright 2017, Florent Thiery
'''
Criticality: Normal
Checks that TLS certificates are valid; if invalid, the user will have to add an exception in his browser
'''
import datetime
import imp
import OpenSSL
import os
import requests
import sys
import ssl

YELLOW = '\033[93m'
GREEN = '\033[92m'
RED = '\033[91m'
DEF = '\033[0m'

if not os.path.isdir('/etc/nginx'):
    print('Nginx not found, skipping test')
    sys.exit(2)

os.chdir(os.path.dirname(__file__))
if not os.path.isfile('../utils.py'):
    print('conf.sh not found')
    sys.exit(1)

es_utils = imp.load_source('es_utils', '../utils.py')
conf = es_utils.load_conf()

conf_servers = (
    ('MS_SERVER_NAME', 'mediaserver'),
    ('MONITOR_SERVER_NAME', 'monitor'),
    ('CM_SERVER_NAME', 'campusmanager'),
)

with open('/etc/hosts', 'r') as fo:
    hosts = fo.read()

for s, d in conf_servers:
    v = conf.get(s)
    if v == d:
        # vhost is using default value, the service is surely not installed
        continue
    if v not in hosts:
        # the domain is not in the hosts file, the service is surely not installed
        continue
    try:
        # further tests
        conn = ssl.create_connection((v, 443))
        context = ssl.SSLContext(ssl.PROTOCOL_TLS)
        sock = context.wrap_socket(conn, server_hostname=v)
        cert = ssl.DER_cert_to_PEM_cert(sock.getpeercert(True))
        x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, cert)
        not_after = x509.get_notAfter().decode('ascii')

        expires = datetime.datetime.strptime(not_after, '%Y%m%d%H%M%SZ')
        print('TLS cert for {} expires at {}'.format(v, expires.isoformat()))

        remaining = expires - datetime.datetime.utcnow()

        if remaining < datetime.timedelta(days=0):
            print('Error, already expired…')
            sys.exit(1)
        elif remaining < datetime.timedelta(days=14):
            print('Warning, will expire soon!')
            sys.exit(3)
        else:
            print('Good, enough time before expiration.')

        url = 'https://%s' % v
        print('Checking TLS certificate of %s' % url)
        requests.get(url)
    except requests.exceptions.SSLError:
        print('%sTLS certificate for %s is not valid%s' % (YELLOW, url, DEF))
        sys.exit(3)

sys.exit(0)